(define (make-frame origin edge1 edge2) 
  (list origin edge1 edge2)) 

(define (frame-origin f) (car f)) 

(define (frame-edge1 f) (cadr f)) 

(define (frame-edge2 f) (caddr f)) 

(define (make-frame origin edge1 edge2) 
  (cons origin (cons edge1 edge2))) 

(define (frame-origin f) (car f)) 

(define (frame-edge1 f) (cadr f)) 

(define (frame-edge2 f) (cddr f)) 
